Hello all

never used the forum before but I wonder if I could get some help on my crash from yesterday.


Quick summary I was flying over the canal to get this shot under a bridge. I've done it many times on this Air 2s and my old Air. I was in Cine mode and about 6 meters from the drone when it just veered to the right, losing height and crashed into the bank and had a little wet dunk too.


Now it's all janky with water going in the camera and sensor/gimbal errors. I can't keep it connected to the USB cable either.


I did pull the video off the card using my phones as the SD card reader but I can't see any DJI files when using the phone as the reader :s

My cache has been playing up ever since I got the drone with some videos cached and some not. This one did not.


I can see from the apps flight data centre my flight and at the time of the crash I was just pushing forward still with no right inputs for it to do what it did.  I had no sensor warnings going under the bridge, I was on top of the bridge and after about 6 meters from clearing the bridge it started the right turn, visably it was banked like it was in a roll.


I'm not sure what information I need to pull off it now and how. I have read the forums a bit and connected to AirData.


https://app.airdata.com/flight/692a264f09de407bbed51b7510e26182/GENERALNotifications

I'll upload the video from the SD card to youtube now.

Upload your log to PhantomHelp instead of AirData to allow others to download the original data.

Please remember that once if your VPS reads a 0.3m height, it initiates landing. And your VPS can be easily reading 0.3 m or even 0.1 m above water, even if you were like 6 meters above of it.
Though, this might not be your case. That turn right in the finish doesn't look right to me as there were no input for that.

Was there any tree branches or birds? That turn isn't natural...

We need the original log to do a better research on this. Those shown on AirData isn't good enough.

FriedChicken_II Posted at 7-26 02:26
Upload your log to PhantomHelp instead of AirData to allow others to download the original data.

Please remember that once if your VPS reads a 0.3m height, it initiates landing. And your VPS can be easily reading 0.3 m or even 0.1 m above water, even if you were like 6 meters above of it.

I will do, cheers

Well not quite sure I understand that, lots of times you are flying lower than your starting position and I've done this many times. So for it to just do this seems odd.

It's wasn't going into landing it just lost itself.

Whilst there are trees etc the section I was in is very clear and I'm right there, looking at it just bank and crash.  You'll see on the video.

Heath-2s Posted at 7-26 02:41
I will do, cheers

Well not quite sure I understand that, lots of times you are flying lower than your starting position and I've done this many times. So for it to just do this seems odd.

Yes I'm waiting for the video. Clearly the case that I've mentioned above doesn't suit your situation. It looks like something made your drone turn right and you were trying your best to compensate that but failed.  It might got hit by a tree branch or a bird, or maybe other bad thing happended. Need to see more before making a conclusion.

Hello there Heath-2s. I am sorry to read and to know what happened to your DJI Air 2S. Since this unfortunate event is happening I would recommend you to contact our DJI support team at https://www.dji.com/support?site=brandsite&from=nav for further assistance.  We have a professional team that will do there best to check what happened to the said drone and will give out the best resolution for this issue. Again I am sorry for the trouble and thank you.

FriedChicken_II Posted at 7-26 02:52
Yes I'm waiting for the video. Clearly the case that I've mentioned above doesn't suit your situation. It looks like something made your drone turn right and you were trying your best to compensate that but failed.  It might got hit by a tree branch or a bird, or maybe other bad thing happended. Need to see more before making a conclusion.

Here you go :p

I've added slow mo at the end of the video.  Nothing there.

https://www.youtube.com/watch?v=eIHiuezg9JI

Heath-2s Posted at 7-26 03:05
Here you go :p

I've added slow mo at the end of the video.  Nothing there.

Now I'm just as confused as you're. It seems that you've managed to correct the heading but the drone still went the other way.

Maybe have a look at your motors and props, to check if there were anything unusual? I don't have a clue from both the log and the video.

Thought it is interesting it started drifting to the right at round the time you went under the bridge.

Was there any strong magnetic interference? Maybe that's why your drone turned rapidly? Maybe try going with a compass and do a field research.

AussieDronePilot Posted at 7-26 03:18
Thought it is interesting it started drifting to the right at round the time you went under the bridge.

Yes maybe at 1:10 you can see a tiny drift before the bigger one at 1:14.

Either that was just a natural drift or the start of it.

This video seemed very similar to your case. Sudden magnetic interference during flight in specific area. And your drone starts to drift away towards a specific direction like spiraling something.

You can't prevent this even if you have calibrated your compass. Some spots are just more dangerous for drones than it seems... I think that if you upload your flight log and video to DJI, they would replace your drone.

FriedChicken_II Posted at 7-26 03:34
You can't prevent this even if you have calibrated your compass. Some spots are just more dangerous for drones than it seems...

Well is water in itself not magnetic... If it had just came from under the bridge, there had been an error there etc I might have understood, but like I say I have done this type of flying and this bridge quite a few times and hence why I was doing it again trying to refine a smooth clip to edit  

Yes maybe that guy with all that snow and atmospheric pressure caused his issue.

I will see what DJI say.

So here's a pic straight after the drone was rescued. The right rear arm had folded back and you can see on both the bank picture and the one I've just taken a couple of little niks in the prop which is to be expected from that crash.

That flight I'd already been up and down the canal like 3 times and the previous flight I was in sport mode belting down the field. I changed battery after that so for a prop to be damaged I don't think so.


Ok can't upload picures. I trimmed it down to 980k and it still wont let me upload.

Heath-2s Posted at 7-26 03:53
Well is water in itself not magnetic... If it had just came from under the bridge, there had been an error there etc I might have understood, but like I say I have done this type of flying and this bridge quite a few times and hence why I was doing it again trying to refine a smooth clip to edit  

Yes maybe that guy with all that snow and atmospheric pressure caused his issue.

It can be very frustrating I'm sorry for your loss and I can't help figuring the problem. All my assumptions don't look right.

Phantom Help data as requested and for anybody else that is interested

https://www.phantomhelp.com/LogViewer/1AY0X47LWMSQWTRCHJF4/#

I wonder if this is a problem related to flying too low over water, confusing the VPS. From the video it seems that it literally started to initiate a kind of sideways movement to the right while in the same time almost completely stopped moving forward.  

Firstly, very sorry for your crash.  I know it makes for a bad day!

Having said that, if I were a betting man, I would put money on your close proximity to the steel guard rail on your left being the likely reason for the circumstances that happened.  I would bet that it influenced your compass in such a way that caused the drone to think it was facing a different direction than it actually was facing.  It is just as you are exiting the close proximity of the guard rail that your heading starts to change rapidly (5m 17.9s).  About 1 second later (5m 19.1s), it looks like you recognized something was going wrong and started trying to correct its heading.

KlooGee Posted at 7-26 04:56
Firstly, very sorry for your crash.  I know it makes for a bad day!

Having said that, if I were a betting man, I would put money on your close proximity to the steel guard rail on your left being the likely reason for the circumstances that happened.  I would bet that it influenced your compass in such a way that caused the drone to think it was facing a different direction than it actually was facing.  It is just as you are exiting the close proximity of the guard rail that your heading starts to change rapidly (5m 17.9s).  About 1 second later (5m 19.1s), it looks like you recognized something was going wrong and started trying to correct its heading.

Hey KlooGee

yes I have since spotted that and wondered. Just thought as I cleared it by a few meters before it started to turn then maybe not, but yes most likely given everything else going up and down the water had been the same :/
The correction was as I could visably see it banking and dropping. Too late by that point as the drone was out of control and you can see with no stick forward it was still just travelling.

cheers

I was flying over the canal to get this shot under a bridge. ... I was in Cine mode and about 6 meters from the drone when it just veered to the right, losing height and crashed into the bank

Trying to match your description with what the data shows ...
Late in the flight you were flying steadily with the right stick full forward and slightly left.
The drone's heading is stable at 348° until 317.8 seconds when the drone strated to rotate clockwise with no corresponding joystick input.
It turns 46° clockwise before before you counteract the rotation with rudder input at 319 seconds and leave the right stick centred and the drone to slow.
The data appears to show a low speed collision at 320.5 seconds, the drone rolls hard to the right and the data stops before the drone can lose any significant height.

The obvious thing that comes too mind when seeing a drone start rotating without rudder input is proximity to a large steel object, deflecting the compass.

Now looking at your video, there's no rotation to match what the sensors indicate.
That's a strong clue that magnetic interference is deflecting the compass even though the drone isn't rotating.

Labroides Posted at 7-26 05:32
I was flying over the canal to get this shot under a bridge. ... I was in Cine mode and about 6 meters from the drone when it just veered to the right, losing height and crashed into the bank

Trying to match your description with what the data shows ...

I suppose with being about 90cm off the ground/water and just being slightly left of centre when entering the bridge so maybe another 100cm all told about 105cm :p

With regards to my inputs though, I am reading this correctly...  I stopped right stick forward at home distance 46.9ft and the drone carried on till say 65ft on impact. As that includes the sideways movement too it still went around 18ft from a speed of 11mph.  My point is just I saw it going and it didn't stop

Heath-2s Posted at 7-26 05:47
I suppose with being about 90cm off the ground/water and just being slightly left of centre when entering the bridge so maybe another 100cm all told about 105cm :p

With regards to my inputs though, I am reading this correctly...  I stopped right stick forward at home distance 46.9ft and the drone carried on till say 65ft on impact. As that includes the sideways movement too it still went around 18ft from a speed of 11mph.  My point is just I saw it going and it didn't stop

Were you responding to my post?
I'm having trouble working out what you are saying?

Labroides Posted at 7-26 05:56
Were you responding to my post?
I'm having trouble working out what you are saying?

sorry man I thought you asked roughly how close I was to the metal side wall on the canal. I was guessing with vertical and horrizontal I was 105cm away from it.

Then I was making my own deductions and asking for clarification that if stopped forward stick movement when I saw the drone losing control but weirdly it still carried on for another 18feet which at 11mph I don't know if this is excessive but from user experience I'd expect it to stop very very quickly in Cine mode and it didn't.

So with magnetic interferance being the probable cause for the hard bank to the right would it also stop it from just stopping when I'd let go of the stick for so long?

Heath-2s Posted at 7-26 06:14
sorry man I thought you asked roughly how close I was to the metal side wall on the canal. I was guessing with vertical and horrizontal I was 105cm away from it.

Then I was making my own deductions and asking for clarification that if stopped forward stick movement when I saw the drone losing control but weirdly it still carried on for another 18feet which at 11mph I don't know if this is excessive but from user experience I'd expect it to stop very very quickly in Cine mode and it didn't.

I had asked about the steel as I hadn't seen the video and was just going from what the data shows.
After I saw the video I deleted the question and added a little about the compass making the data look like the drone was rotating.

If you were only 1 metre from that armco, that would be enough to upset the compass but your forward momentum kept the drone moving forward beyond the magnetic interference of the steel rail, but with the drone's steering slightly affected.

Being so close above water, the VPS would have tried to help with horizontal position holding (and braking).
But the water surface is unsuitable for VPS, so the braking didn't work.